Biomedical subjects

W Kawahara

Publications and source records attributed to W Kawahara.

3 recordsLinked to original sources

PubMed1978

Comparative effect of calcium and of the adrenergic system on calcitonin secretion in man.

This study evaluated the effects of adrenergic agents on immunoreactive calcitonin (iCT) secretion in normal man, and compared the time course and magnitude of these adrenergic effects with those caused by modifying calcium (Ca) ion concentration. Ca infusion (15 mg Ca++/kg iv in 4 h) significantly increased plasma iCT within 1 h, reaching 140 +/- 8% of baseline at 4 h. EDTA (50 mg/kg iv in 2 h) significantly decreased plasma iCT within 15 min, with nadir value of 53 +/- 4.9% of baseline at 2 h. The beta-adrenergic agonist, isoproterenol, significantly increased plasma iCT with 5 min, reaching 136 +/- 5.9% of baseline at 30 min. The alpha-adrenergic antagonist, phentolamine, significantly increased iCT within 15 min, reaching 132 +/- 8.6% of baseline at 45 min. The beta-adrenergic antagonist, propranolol, significantly suppressed iCT with 15 min, reaching 51.8 +/-6.3% of baseline at 2 h. Therefore, 1) the adrenergic system (without induced change in serum Ca) can modify CT secretion to as great a degree as can change in Ca ion concentration induced by standard Ca and EDTA infusion tests and 2) even basal secretion of CT can be modified by adrenergic influences. These data strongly suggest 1) that the adrenergic system is an effective modifier of CT secretion and 2) that the adrenergic system, as well as Ca ion concentration, may play an improtant physiological role in control of CT secretion in man.

Adult↗

PubMed1978

Radioimmunoassay of calcitonin in the plasma of rhesus monkey and man.

We describe a radioimmunoassay for rhesus monkey and human immunoreactive calcitonin, in which a selected goat anti-human calcitonin antiserum, 131I-labeled synthetic human calcitonin tracer, and purified synthetic human calcitonin standards were used. The mean basal concentration of calcitonin in normal monkey plasma (254 microgram/liter) was not significantly different from that in normal human plasma (217 microgram/liter). The data indicate that the method is sensitive (lower limit of detection, 5 ng/liter), specific, accurate, and reproducible (coefficient of variation, 1-11% over a wide range of concentrations). Monkey calcitonin response to changes in plasma calcium concentration is similar to that in man, with significant correlation between calcium and calcitonin concentrations. Use of this radioimmunoassay for monkey and human calcitonin allows the monkey to be used in further studies of factors regulating secretion, function, and metabolism of calcitonin under various experimental conditions that would not be feasible in man.

Animals↗

PubMed1977

Radioimmunoassay of parathyroid hormone (parathyrin) in monkey and man.

A radioimmunoassay for rhesus monkey and human immunoreactive parathyrin was developed in which a selected anti-bovine parathyrin antiserum, radioiodinated purified bovine parathyrin tracer, and human parathyroid tissue-culture media standards were used. The resulting data indicate that (a) the method is sensitive, specific, accurate and reproducible; (b) it is valid for both the rhesus monkey and the human; (c) the serum immunoreactive parathyrin concentration of the monkey is essentially the same as that in man; (d) monkey immunoreactive parathyrin responds to changes in serum calcium concentration similarly to that in man; and (e) the rhesus monkey is therefore a suitable species in which to study parathyroid physiology, from which conclusions can be applied to the human.

Adult↗